IMHO, remodel in SW and use judicious simplification. If it takes less than 10 hours to remodel the part then you have saved time and headaches.
Alternatively, use local mesh refinement. I've found that sometimes a standard mesh of relatively smaller size will allow parts to be meshed and give valid/useful results.
I didn't think you could do anything with .stl files. At least I haven't been able to. I've had better luck with TinkerCAD.
Have you checked to make sure it is really a solid body with no loose/free edges/surfaces/etc.?
This part is a nightmare. I don't see remodeling it being an option but it's something to consider, and I think you're correct that there are way too many loose edges, faces, etc.
I'm not sure I'll be able to mesh it as is
If you can't remodel the part and you can't export a clean set of geometry with no open surfaces, cracks, small-features, etc., then you're pretty much out of luck; the only options I can think of are:
- Export the part from Pro/E under a different file structure. Parasolid is a good choice (.x_t).
- Try cleaning up and simplifying the geometry in Pro/E.
- Try cleaning up the part in SW.
If you can do any of this, then the only other option would be to use a third-part FEA package (ANSYS, FEMAP, etc.); they typically have geometry clean-up functions to solve issues like this.
step 1 import diagnostics, make sure there are no features
step 2, shouldn't do anything but ctrl-q with VOR enabled
step 3, tools > check
step 4, interference detection if multibody part
these should be the standard for basically all models
but remember you're asking a software to discretize an already discretized model, you're gonna have a hard time doing that
remodeling or finding a software to smooth it out is probably your best bet